In the era of large Galactic surveys like Gaia, we require sophisticated dynamical modeling tools to turn the amount and quality of the observed stellar data (positions and velocities) into reliable constraints on the Milky Way’s overall structure. In this blackboard talk, I introduce RoadMapping, a dynamical modeling machinery for the Galactic disk using action-based distribution functions that I developed during my PhD. I outline the idea behind the technique, the tests I performed to demonstrate its robustness, and – last but not least – I present brand-new measurements of the Galactic gravitational potential using data from Gaia DR1 and RAVE.